also eucaryotic, "characterized by well-defined cells (with nuclei and cell walls)," 1957, from French eucaryote (1925), from Greek eu "well, good" (see eu-) + karyon "nut, kernel" (see karyo-). Related: Eukaryote; eucaryote.
word-forming element, in modern use meaning "good, well," from Greek eus "good," eu "well" (adv.), also "luckily, happily" (opposed to kakos), as a noun, "the right, the good cause," from PIE *(e)su- "good" (source also of Sanskrit su- "good," Avestan hu- "good"), originally a suffixed form of root *es- "to be." In compounds the Greek word had more a sense of "greatness, abundance, prosperity," and was opposed to dys-.
before vowels kary-, word-forming element used since c. 1874 in biological terms referring to cell nuclei, from Greek karyon "nut, kernel," possibly from PIE root *kar- "hard," but Beekes leans toward the notion that it is a Pre-Greek word.
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Definitions of eukaryotic from WordNet
having cells with `good' or membrane-bound nuclei;